'''Major depressive disorder''' (also known as '''major depression''', '''unipolar depression''', '''unipolar disorder''', or '''clinical depression''') is a [[mental disorder]] typically characterized by a pervasive [[depression (mood)|low mood]], low [[self-esteem]], and loss of interest or pleasure in usual activities. The term was coined by the [[American Psychiatric Association]] in the 1980 version of the [[Diagnostic and Statistical Manual of Mental Disorders]] (DSM-III) classification for the [[syndrome|symptom cluster]], and has become widely used. The general term ''[[depression (mood)|depression]]'' is often used to describe the disorder, but since it is also used to describe a temporary sad or depressed mood, more precise terminology is preferred in clinical use and research. Major depression is often a disabling condition which adversely affects a person's family, work or school life, sleeping and eating habits, and general health. In the United States around 3.4% of people with major depression commit [[suicide]], and up to 60% of all people who commit suicide have depression or another [[mood disorder]].

'''Major depressive disorder''' (also known as '''major depression''', '''unipolar depression''', '''unipolar disorder''', or '''clinical depression''') is a [[mental disorder]] typically characterized by a pervasive [[depression (mood)|low mood]], low [[self-esteem]], and loss of interest or pleasure in usual activities. The term was coined by the [[American Psychiatric Association]] in the 1980 version of the [[Diagnostic and Statistical Manual of Mental Disorders]] (DSM-III) classification for the [[syndrome|symptom cluster]], and has become widely used. The general term ''[[depression (mood)|depression]]'' is often used to describe the disorder, but since it is also used to describe a temporary sad or depressed mood, more precise terminology is preferred in clinical use and research. Major depression is often a disabling condition which adversely affects a person's family, work or school life, sleeping and eating habits, and general health. In the United States around 3.4% of people with major depression commit [[suicide]], and up to 60% of all people who commit suicide have depression or another [[mood disorder]].

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{{Depression}}

== Symptoms and signs==

== Symptoms and signs==

According to the [[National Institute of Mental Health|U.S. National Institute of Mental Health]], major depression is a serious illness that affects a person's family, work or school life, sleeping and eating habits, and general health.<ref name="NIMHPub">{{cite web|title=Depression|publisher = [[National Institute of Mental Health]] (NIMH)|url = http://www.nimh.nih.gov/health/publications/depression/nimhdepression.pdf|accessdate = 2008-09-07|format=PDF}}</ref> The impact of depression on functioning and well-being has been equated to that of chronic medical conditions such as [[Diabetes mellitus|diabetes]].<ref>{{cite journal |author=Hays RD, Wells KB, Sherbourne CD, ''et al.'' |year=1995 |title=Functioning and well-being outcomes of patients with depression compared with chronic general medical illnesses |journal=Archives of General Psychiatry |volume=52 |issue=1 |pages=11–19 |pmid=7811158}}</ref>

According to the [[National Institute of Mental Health|U.S. National Institute of Mental Health]], major depression is a serious illness that affects a person's family, work or school life, sleeping and eating habits, and general health.<ref name="NIMHPub">{{cite web|title=Depression|publisher = [[National Institute of Mental Health]] (NIMH)|url = http://www.nimh.nih.gov/health/publications/depression/nimhdepression.pdf|accessdate = 2008-09-07|format=PDF}}</ref> The impact of depression on functioning and well-being has been equated to that of chronic medical conditions such as [[Diabetes mellitus|diabetes]].<ref>{{cite journal |author=Hays RD, Wells KB, Sherbourne CD, ''et al.'' |year=1995 |title=Functioning and well-being outcomes of patients with depression compared with chronic general medical illnesses |journal=Archives of General Psychiatry |volume=52 |issue=1 |pages=11–19 |pmid=7811158}}</ref>

Revision as of 14:32, September 30, 2013

Major depressive disorder (also known as major depression, unipolar depression, unipolar disorder, or clinical depression) is a mental disorder typically characterized by a pervasive low mood, low self-esteem, and loss of interest or pleasure in usual activities. The term was coined by the American Psychiatric Association in the 1980 version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) classification for the symptom cluster, and has become widely used. The general term depression is often used to describe the disorder, but since it is also used to describe a temporary sad or depressed mood, more precise terminology is preferred in clinical use and research. Major depression is often a disabling condition which adversely affects a person's family, work or school life, sleeping and eating habits, and general health. In the United States around 3.4% of people with major depression commit suicide, and up to 60% of all people who commit suicide have depression or another mood disorder.

Contents

Symptoms and signs

According to the U.S. National Institute of Mental Health, major depression is a serious illness that affects a person's family, work or school life, sleeping and eating habits, and general health.[1] The impact of depression on functioning and well-being has been equated to that of chronic medical conditions such as diabetes.[2]

A person suffering a major depressive episode usually experiences a pervasive low mood, or loss of interest or pleasure in favored activities. Depressed people may be preoccupied with feelings of worthlessness, inappropriate guilt or regret, helplessness or hopelessness.[3] Other symptoms include poor concentration and memory, withdrawal from social situations and activities, reduced libido (sex drive), and thoughts of death or suicide. Insomnia is common: in the typical pattern, a person wakes very early and is unable to get back to sleep.[4]Hypersomnia, or oversleeping, is less common.[4] Appetite often decreases, with resulting weight loss, although increased appetite and weight gain occasionally occur.[3] The person may report persistent physical symptoms such as fatigue, headaches, digestive problems, or chronic pain; this is a typical presentation of depression, according to the World Health Organization's criteria of depression, in developing countries.[5] Family and friends may perceive that the person is either agitated or slowed down.[4] Older people with depression are more likely to show cognitive symptoms of recent onset, such as forgetfulness and to show a more noticeable slowing of movements.[6] In severe cases, depressed people may experience psychotic symptoms such as delusions or, less commonly, hallucinations, usually of an unpleasant nature.[7][8]

Children may display an irritable rather than depressed mood,[3] and show different symptoms depending on age and situation.[9] Most exhibit a loss of interest in school and a decline in academic performance. Children with depression may be described as clingy, demanding, dependent, or insecure.[4] Diagnosis may be delayed or missed when symptoms are interpreted as normal moodiness.[3]

Diagnosis

Major depressive episode

A major depressive episode is characterized by the presence of a severely depressed mood that persists for at least two weeks.[3] Episodes may be isolated or recurrent and are categorized as mild (few symptoms in excess of minimum criteria), moderate, or severe (marked impact on social or occupational functioning). An episode with psychotic features—commonly referred to as psychotic depression—is automatically rated as severe. If the patient has had an episode of mania or markedly elevated mood, a diagnosis of bipolar disorder is made instead.[10] Depression without mania is sometimes referred to as unipolar because the mood remains at one emotional state or "pole".[11]

DSM-IV-TR excludes cases where the symptoms are a result of bereavement, although it is possible for normal bereavement to evolve into a depressive episode if the mood persists and the characteristic features of a major depressive episode develop.[12] The criteria have been criticized because they do not take into account any other aspects of the personal and social context in which depression can occur.[13] In addition, some studies have found little empirical support for the DSM-IV cut-off criteria, indicating they are a diagnostic convention imposed on a continuum of depressive symptoms of varying severity and duration:[14] excluded are a range of related diagnoses, including dysthymia which involves a chronic but milder mood disturbance,[15]Recurrent brief depression which involves briefer depressive episodes,[16][17]Minor depressive disorder which involves only some of the symptoms of major depression,[18] and Adjustment disorder with depressed mood which involves low mood resulting from a psychological response to an identifiable event or stressor.[19]

Subtypes

The DSM-IV-TR recognizes several subtypes, which are sometimes called "course specifiers":

Atypical depression is characterized by mood reactivity (paradoxical anhedonia) and positivity, significant weight gain or increased appetite (comfort eating), excessive sleep or sleepiness (hypersomnia), a sensation of heaviness in limbs known as leaden paralysis, and significant social impairment as a consequence of hypersensitivity to perceived interpersonal rejection.[20]

Catatonic depression is a rare and severe form of major depression involving disturbances of motor behavior and other symptoms. Here the person is mute and almost stuporose, and either remains immobile or exhibits purposeless or even bizarre movements. Catatonic symptoms also occur in schizophrenia or in manic episodes, or may be caused by neuroleptic malignant syndrome.[21]

Melancholic depression is characterized by a loss of pleasure in most or all activities, a failure of reactivity to pleasurable stimuli, a quality of depressed mood more pronounced than that of grief or loss, a worsening of symptoms in the morning hours, early morning waking, psychomotor retardation, excessive weight loss (not to be confused with anorexia nervosa), or excessive guilt.[22]

Other types of depression, not categorized as Major depressive disorder, are recognized by the DSM-IV-TR:

Postpartum depression (Mild mental and behavioral disorders associated with the puerperium, not elsewhere classified in ICD-10[23]) refers to the intense, sustained and sometimes disabling depression experienced by women after giving birth. Postpartum depression, which has incidence rate of 10–15% among new mothers, typically sets in within three months of labor, and lasts as long as three months.[24][25]

Seasonal affective disorder is a form of depression in which depressive episodes come on in the autumn or winter, and resolve in spring. The diagnosis is made if at least two episodes have occurred in colder months with none at other times, over a two-year period or longer.[26]

Other ways of categorizing depression have been used historically and they include:

Differential diagnoses

In order to decide that major depressive disorder is the most likely diagnosis, the probability of several other potential diagnoses must be considered, including the following:

Dysthymia is a chronic, milder mood disturbance in which a person reports a low mood almost daily over a span of at least two years. The symptoms are not as severe as those for major depression, although people with dysthymia are vulnerable to secondary episodes of major depression (sometimes referred to as double depression).[15]

Adjustment disorder with depressed mood is a mood disturbance appearing as a psychological response to an identifiable event or stressor, in which the resulting emotional or behavioral symptoms are significant but do not meet the criteria for a major depressive episode.[19]

Bipolar disorder, previously known as manic-depressive disorder, is a condition in which depressive phases alternate with periods of mania or hypomania. Although depression is currently categorized as a separate disorder, there is ongoing debate because individuals diagnosed with major depression often experience some hypomanic symptoms, indicating a mood disorder continuum.[27]

History, Theory & Cause

Depression is the modern terminology for what in earlier times was described as Melancholia. As early as the 4th and 5th centuries BC, Melancholia was described as "aversion to food, despondency, sleeplessness, irritability, restlessness," as well as the statement that "Grief and fear, when lingering, provoke melancholia". It is now generally believed that melancholia was the same phenomenon as what is now called clinical depression.

Theory & Etiology (Cause)

Major depression is generally seen as a mental disorder with multiple causes.
The understanding of the nature and causes of depression has evolved over the centuries; nevertheless, many aspects of depression are still not fully understood, and are the subject of debate and research. Both psychological and biological causes have been proposed. Psychological theories and treatments are based on ideas about the personality, interpersonal communication, and unduly negative thoughts. The monoamine chemicals serotonin, norepinephrine, and dopamine are naturally present in the brain and assist communication between nerve cells. Monoamines have been implicated in depression, and most antidepressants work to increase the active levels of at least one.

From the evolutionary standpoint, major depression might be expected to reduce an individual's ability to reproduce. Some evolutionary explanations for the apparent contradiction between biopsychosocial, psychological and psychosocial hypotheses and the high heritability and prevalence of depression are explained by the proposal that certain components of depression are adaptations[28] such as the mechanisms underlying behaviors relating to attachment and social rank.[29] Evolutionary theorists view the condition as an adaptation to regulate relationships or resources, although it may be unwanted or disordered in modern environments.[30] From this perspective, depression can be seen as "a species-wide evolved suite of emotional programmes that are mostly activated by a perception, almost always over-negative, of a major decline in personal usefulness, that can sometimes be linked to guilt, shame or perceived rejection".[31]

Depression appears to be related to disruptions in the circadian rhythm, or human biological clock.

Major depression may also be caused in part by an overactive hypothalamic-pituitary-adrenal axis (HPA axis) that is similar to the neuro-endocrine response to stress. Investigations reveal increased levels of the hormone cortisol, enlarged pituitary and adrenal glands, and a blunted circadian rhythm. Oversecretion of corticotropin-releasing hormone from the hypothalamus is thought to drive this, and is implicated in the cognitive and arousal symptoms.[32] The REM stage of sleep, in which dreaming occurs, tends to be especially quick to arrive, and especially intense, in depressed people. Although the precise relationship between sleep and depression is mysterious, the relationship appears to be particularly strong among those whose depressive episodes are not precipitated by stress. In such cases, patients may be especially unaffected by therapeutic intervention.[33]

The hormone estrogen has been implicated in depressive disorders due to the increase in risk of depressive episodes after puberty, the antenatal period, and reduced rates after menopause.[34] Conversely, the premenstrual and postpartum periods of low estrogen levels are also associated with increased risk.[34] The use of estrogen has been under-researched, and there although some small trials show promise in its use to prevent or treat depression, the evidence for its effectiveness is not strong.[34] Estrogen replacement therapy has been shown to be beneficial in improving mood in perimenopause, but it is unclear if it is merely the menopausal symptoms that are being reversed.[34]

Social depreciation, discriminative behaviour towards an individual occurring either explicitly or implicitly (i.e. the director is unaware of their negative behaviour towards the receiver), peer pressure (whether implicit (i.e. a natural attempt to conform to social standards, or to compete with social pressure)) or explicit and desynchronized social interaction primarily act as a social stimulus for depression. The absence of social sync may occur due to an imbalance amidst independence and external interaction (i.e. socializing) with their environment; independence would thus be an individual synchronizing with their internal mechanisms, ergo causing them to develop extravagant abilities (e.g. eidetic, excessive episodic or categorical memory, abnormal academia (depending on age) or abilities to achieve excess results in challenges of various subjects). Such abilities may occur as being savant-like. A synchronization period may result in de-synced abilities intervening with both aspects (i.e. the individual may lose their independence and ability to socialize as they subjectively attempt to balance their cognition). Thus, as a primary counteract to social/independence impairment, an individual would require balance amidst internal/external synchronization.

Alternative social stimuli for depression may present as requirement for relationships; an individual may find peer pressure directed towards a need for a relationship with either sex. Furthermore, an evolutionary conflict may occur between a social environment; an individual may lack the ability to sync (or otherwise refuse and thus, adhering to their own standards) with their social environment, and with additional instinctual pressure to sustain a relationship, a conflict may transpire thereby inadvertently causing depression.

Various aspects of personality and its development are integral in the occurrence and persistence of depression.[35] Although episodes are strongly correlated with adverse events, how a person copes with stress also plays a role.[35] Low self-esteem, learned helplessness, and self-defeating or distorted thinking are related to depression. Depression may also be connected to feelings of religious alienation;[36] conversely, depression is less likely to occur among those with high levels of religious involvement.[37] It is not always clear which factors are causes or effects of depression, but in any case depressed persons who are able to make corrections in their thinking patterns often show improved mood and self-esteem.[38]

Poverty and social isolation are associated with increased risk of psychiatric problems in general;[39] a study in Providence, Rhode Island following children from birth found that family disruption and low socioeconomic status in early childhood were linked to an increased risk of major depression in later life;[40] this was noted to be independent of later adult social status and related to various social inequalities, the consequences of which may be more severe for women.[41] Childhood emotional, physical, sexual abuse, or neglect are also associated with increased risk of developing depressive disorders later in life.[42][39] Disturbances in family functioning, such as parental (particularly maternal) depression, severe marital conflict or divorce, death of a parent, or other disturbances in parenting are additional risk factors.[39]

In adulthood, stressful life events are strongly associated with the onset of major depressive episodes; a first episode is more likely to be immediately preceded by stressful life events than are recurrent ones.[43] The relationship between stressful life events and social support has been a matter of some debate. Perhaps the lack of social support only increases the likelihood that life stress will lead to depression. More likely, however, the absence of social support constitutes a form of strain that provokes depression directly.[44] There is evidence that neighborhood social disorder, for example, due to crime or illicit drugs, is a risk factor, and that a high neighborhood socioeconomic status, with better amenities, is a protective factor. Adverse workplace conditions, particularly demanding jobs with little scope for decision-making, are associated with depression, although diversity and confounding factors make it difficult to confirm the relationship is causal.[45] There is mixed evidence regarding the role of social capital (features of social organization including interpersonal trust, civic engagement and cooperation for mutual benefit).[46]

Certain risk factors have been identified that predispose people towards depression. Affective disorders, of which Unipolar depression is one type, have an approximate heritability of 60-70%, occuring more frequently in women. Men on the other hand tend to suffer Alcoholism more frequently, which can be indicative of underlying depression. Certain studies have suggested a genetic cause for depression, such as a faulty gene for the synthesis and/or transport of serotonin. Social approaches emphasize the role of traumatic Life Events in the depressed person's history.

The diagnosis and assessement of major depressive disorder is based on the patient's self-reported experiences, behavior reported by relatives or friends, and mental state. There is no laboratory test for major depression, although physicians generally request tests for physical conditions that may cause similar symptoms. The most common time of onset is between the ages of 30 and 40 years, with a later peak between 50 and 60 years. Major depression occurs about twice as frequently in women than men, although men are at higher risk for suicide.
The accurate diagnosis of depression is an important issue. In the past evidence suggests the condition was often missed, particularly in the elderly and in children

Women who suffer from depression far more frequently than men (HOW MUCH), approximately 1 in 3??? women will suffer from Depression at some point in their lives, compared to only 1 in 10??? men. Reasons for this include such causes as postnatal depression, hormonal influences due to mood instability at different stages in the menstrual cycle, and hormonal changes after menopause. Culturally it has been suggested that women suffer depression more frequently than men because they are more repressed and have less control over their lives than men. To counter this it has been suggested that men are unable to express their feelings as freely as women and instead suffer from conditions such as Alcoholism. There is possible co-morbidity with eating disorders in women and rarely with men.

As mentioned above, men suffer more frequently from alcoholism, which may be a sign of underlying depression. There is a significantly higher risk of suicide in young men compared to women of the same age. It seems that men are more likely to be successful in suicide atttempts than women, as there are fewer depressed men in any age group than women.

Depression is often misdiagnosed in children, and there is some controversy surrounding prescription of anti depressants to children. Certain anti-depressants are no longer recommended for prescription to children in the UK because of the potential risk of the drugs interfering with the development of the brain.

Depression strikes the elderly more frequently than it does the young. In part this is due to deterioration of the brain in elderly people, and can occur comorbidly with diseases such as alzheimers, parkinsons and following conditions such as stroke. It has also been suggested that a sedentiary lifestyle with little exercise can contribute to depression. Finally, aging people may become depressed after the death of a partner or loved one.

Sociocultural aspects

Even today, people's conceptualizations of depression vary widely, both within and among cultures. "Because of the lack of scientific certainty," one commentator has observed, "the debate over depression turns on questions of language. What we call it—'disease,' 'disorder,' 'state of mind'—affects how we view, diagnose, and treat it."[47] There are cultural differences in the extent to which serious depression is considered an illness requiring personal professional treatment, or is an indicator of something else, such as the need to address social or moral problems, the result of biological imbalances, or a reflection of individual differences in the understanding of distress that may reinforce feelings of powerlessness, and emotional struggle.[48][49]

The diagnosis is less common in some countries, such as China. It has been argued that the Chinese traditionally deny or somatize emotional depression (although since the early 1980s the Chinese denial of depression may have modified drastically).[50] Alternatively, it may be that Western cultures reframe and elevate some expressions of human distress to disorder status. Australian professor Gordon Parker and others have argued that the Western concept of depression "medicalizes" sadness or misery.[51][52] There has also been concern that the DSM, as well as the field of descriptive psychiatry that employs it, tends to reify abstract phenomena such as depression, which may in fact be social constructs.[53][54] American archetypal psychologistJames Hillman writes that depression can be healthy for the soul, insofar as "it brings refuge, limitation, focus, gravity, weight, and humble powerlessness."[55] Hillman argues that therapeutic attempts to eliminate depression echo the Christian theme of resurrection, but have the unfortunate effect of demonizing a soulful state of being.

There has been a continuing discussion of whether neurological disorders and mood disorders may be linked to creativity, a discussion that goes back to Aristotelian times.[56][57] British literature gives many examples of reflections on depression.[58] English philosopher John Stuart Mill experienced a several-months-long period of what he called "a dull state of nerves," when one is "unsusceptible to enjoyment or pleasurable excitement; one of those moods when what is pleasure at other times, becomes insipid or indifferent". He quoted English poet Samuel Taylor Coleridge's "Dejection" as a perfect description of his case: "A grief without a pang, void, dark and drear, / A drowsy, stifled, unimpassioned grief, / Which finds no natural outlet or relief / In word, or sigh, or tear."[59][60] English writer Samuel Johnson used the term "the black dog" in the 1780s to describe his own depression,[61] and it was subsequently popularized by depression sufferer former British Prime Minister Sir Winston Churchill.[61]

Historical figures were often reluctant to discuss or seek treatment for depression due to social stigma about the condition, or due to ignorance of diagnosis or treatments. Nevertheless, analysis or interpretation of letters, journals, artwork, writings or statements of family and friends of some historical personalities has led to the presumption that they may have had some form of depression. People who may have had depression include American-British writer Henry James[63] and American president Abraham Lincoln.[64] Some well-known contemporary people with possible depression include Canadian songwriter Leonard Cohen[65] and American playwright and novelist Tennessee Williams.[66] Some pioneering psychologists, such as Americans William James[67][68] and John B. Watson,[69] dealt with depression in their adulthoods.

Both William James and John Stuart Mill found relief from their depression in literature. For James, who was nearly driven to suicide during his depression, the choice to believe in free will was instrumental in overcoming this condition.[67] This choice was inspired by an essay about free will by French philosopher Charles-Bernard Renouvier.[68] Upon reading this essay, James no longer felt that "suicide [was] the most manly form to put [his] daring into," and declared, "now I will go a step further with my will, not only act with it, but believe as well; believe in my individual reality and creative power."[67] Mill took solace in the work of English poet William Wordsworth.[59] Mill wrote that, "What made Wordsworth's poems a medicine for my state of mind, was that they expressed, not mere outward beauty, but states of feeling, and of thought coloured by feeling, under the excitement of beauty."[59]

Social stigma of major depression is widespread, and contact with mental health services reduces this only slightly. Public opinions on treatment differ markedly to those of health professionals; alternative treatments are held to be more helpful than pharmacological ones, which are viewed poorly.[70] The Royal College of Psychiatrists and the Royal College of General Practitioners conducted a joint Five-year Defeat Depression campaign to educate and reduce stigma from 1992 to 1996;[71] a MORI study conducted afterwards showed a small positive change in public attitudes to depression and treatment.[72]